Creating a flow to update a Sahrepoint list but cannot find the filed i need

[AgainOpen]

 Hello! i need help please.

I created a flow that takes the information on a Form and creates a line in a Sharepoint List, and at the same time it send and email asking for approval.

If the person receiving the email approves the request, i want the same List to be updates with the name of the approver. So far i am not being able to do that - at least not with the fields that are coming up for me to use. Any thoughts or suggestions please? any dynamic formula i can use? 

I am attaching a pic for reference. Thank you

[Expiscornovus]

Hi @AgainOpen,

If there is only one email in the To you could use an expression with collects the e-mail address and concats it with a 'i:0#.f|membership|' to turn it into a claims value.

Below is an example of such an expression.

You can add that as a custom item to the Release Approver Claims field in the expression editor.

concat('i:0#.f|membership|', actions('Send_an_email_(V2)')['inputs']['parameters']['emailMessage/To'])